COMPARATIVE ANALYSIS OF THE CHEMICAL COMPOSITION AND FEATURES OF SURFACE MICROBIAL COMPLEXES OF LICHENS AND THEIR GROWTH SUBSTRATES

Abstract

The aim of the study was a comparative analysis of the chemical composition and features of the surface microbial complexes of three species of epigeic lichens (Cladonia rangiferina (L.), Cetraria islandica (L.), Peltigera horizontalis (Huds.)), one species of epiphytic lichen (Hypogymni aphysodes (L.) Nyl.) and their growth substrates. It was found that the accumulation of inorganic ions by epigeic lichens exceeds their content in the soil by 4–450 times. Maximum biochemical mobility is characteristic of nutrients (potassium ions, phosphate ions). P. horizontalis and C. islandica were characterized by high biochemical mobility of copper and zinc, and H. physodes of cadmium and lead, and therefore these species of lichens can be considered bioaccumulators of these elements. The epiphytic lichen H. physodes was characterized by a relatively high content of phenolic compounds, which indicates its good antioxidant properties. Different physiological groups made the maximum contribution to the structure of microbial populations on the surface of lichens. Nitrogen-fixing bacteria dominated in the microbial complex in the epiphytic lichen H. physodes, and ammonifiers in the epigeic lichens. There is a direct correlation between the number of ammonifiers and the total number of microorganisms on the surface of epigeic lichens and their number in the soil under lichens. The gram-positive spore bacterium Bacillus polymyxa was isolated from the surface of the leafy lichen C. rangiferina (L.) into a pure culture, for which a high antagonistic activity was established with respect to phytopathogenic fungi pp. Fusarium and Alternaria. In the future, this strain can become the basis for the creation of an environmentally friendly biological product to combat plant diseases.